GIS and Evidence-Based Policy Making - Chapter 7 doc

7 Using GIS to Identify Social Vulnerability in Areas of the United Kingdom That Are at Risk from Flooding Tom Kieron Whittington CONTENTS 7.1 Introduction 133 7.1.1 Background 134 7.1.2 Requirement Study 135 7.1.3 Aims 139 7.2 Methods 140 7.2.1 Index of Social Vulnerability 140 7.2.2 Index of Flood Probability 144 7.2.3 Combined Index of Flood Vulne rability 146 7.3 Results 146 7.3.1 Index of Social Vulnerability 146 7.3.2 Index of Flood Probability 148 7.3.3 Combined Index of Flood Vulne rability 150 7.4 Discussion 151 7.4.1 Evaluation of Results 151 7.4.2 Interface Potential 153 7.4.3 Modifiable Areal Unit Problem (MAUP) 154 7.5 Conclusions 155 7.5.1 Answering the Research Questions Posed 155 7.5.2 Developing the Model for Use within the Flood Industry 156 References 156 7.1 Introduction Around 5 million people in 2 million properties live in flood-risk areas in England and Wales (Environment Agency, 2000). Property worth over ß 2007 by Taylor & Francis Group, LLC. £200 billion and agricultural land worth approximately £7 billion are poten- tially at risk of flooding (HR Wallingford, 2000). The floods of Easter 1998 and autumn 2000 gave the United Kingdom an important reminder of a hazard that, though ever present, has been neglected by society in recent times. Many organizations are encouraged to deal with the problem, which is predicted to increase in frequency in the future due to climate change and continued urbanization of the floodplain (Price and McInally, 2001). There is a rise in the philosophical approach of ‘‘living with the hazard’’ (Smith and Ward, 1998) that focuses on flood warning and emergency planning, than flood prevention. Initiatives to help communities to help themselves are therefore high on the agenda but require a clear understanding of the social variability and different needs of communities at risk. It is the high profile of the field of research that motivates this project into establishing how geographical information systems (GIS) may be used to improve flood warning, and emergency planning and response in the United Kingdom. To determine how the technology could be best put to use with im mediate effect, a requirements study has been accomplished from a literature review and interviews with the main organizations involved in flood warning, planning, and research in the United Kingdom. The conclusion of the requirement study identifies that the spatial distribu- tion of vulnerable groups living within the floodplain is a prime target for research, and this group would benefit greatly from GIS investigation. This research attempts to bring together social-vulnerability studies and flood-probability data with GIS technology to produce a high-resolution index of flood vulnerability (IFV). A number of applications demonstrate how the index and some of the data layers used in its creation may be used to improve the efficiency and quality of flood managers’ decision-making. During a flood emergency, planners can quickly identify different groups of people with different social nee ds and can thus disseminate resources appropriately. Alternatively, flood-warning education can be adapted for different communities identified by their postcode. The final index produced is a prototype tool, which requires refinement, but demonstrates how exist- ing studies could be improved with the inclusion of GIS technology. 7.1.1 Background The next century may see apparent increases in CO 2 due to human activities resulting in climate change and consequently flooding from increased intensity and frequency of rainfall and sea-level rise (Price and McInally, 2001). Most flood-prevention schemes can be expected to fail if a high-level flood scenario occurs, and there are many locations where an engineering solution is impractical or could lead to considerable damage to the envir- onment (Borrows, 1999; Environment Agency, 2001). The expansion of urbanized areas can create the risk of more-frequent flood situations where increased precipitation results in greater runoff (Environment Agency, 2001; Price and McInally, 2001). Around 5 million people in ß 2007 by Taylor & Francis Group, LLC. 2 mi llion pro perties are vulne rable to flood risk in Engla nd and Wal es (Env ironmen t Agenc y, 2000); the flood leve ls during the Oct ober 2000 floods were the highest on record in many location s, and 10,000 proper ties were affecte d (Enviro nment Agenc y, 2001). The Bette r Regul ation Task Force (2000) re commen ds that policy make rs consid er vulne rable peop le at all st ages of their work, with gre atest consi d- eratio n to in clude vulnerabi lity im pact assessm ents. Knowl edge of where social differen ces lie with in commun ities poten tially at ris k from floodi ng and the general natur e of their circumst ances is needed to bette r target publi c aware ness informati on and to resp ond appropri ately to emerge ncy situat ions (Mor row, 1999; Tuns tall, 199 9; Blyth et al., 2001; Envi ronment Agenc y, 2001). On e of the mai n reasons for targetin g vuln erable gro ups is the desire to concen trat e on the worst affec ted areas and popu lation (Jaspar s and Shoham 1999); emerge ncy plan ners need to know who they are and wh ere they are concen trated (Mor row, 199 9). Perform ance of flood forecast ing and war ning syst ems appear s to be poor in the Un ited Kin gdom (Hag gett, 1998; Horn er, 2000; Penning- Rows ell et al., 2000; Envi ronment Agenc y, 2001) but wil l contin ue to im prove, pro vided that the rig ht infor- mation can be deli vered in advanc e to the right peop le (FHRC , 200 1). There is a need to devel op accura te flood- hazar d maps and flood- rescue action plans for hazard -prone areas (Rant akokko, 1999). The Environ ment Agenc y has created the ind icative floodpl ain map usin g historical and rainfal l catchmen t mode ls (e.g., ISIS and MIKE11) . The mapped floodplai n boun daries are disaggr egated to unit postc odes to a ssist publ ic iden tifica- tion of risk, but there is a mi smatch bet ween postc ode uni ts and iden tified flood- risk areas (Plough er, 2000). Boyle et al. (1998) discrimi nate the flood- plain into uni ts def ined by the qua ntifica tion and spatia l variabi lity of fl ood hazard . Flood-pr obabili ty contours are create d with hydrol ogical mode ling of flood flow rates assoc iated with differen t return-pe riods (the flood fre- quency in years). The use of GIS in this typ e of hazar d exposur e pro vides an efficient and accurate assessment for areas prone to flooding (Boyle et al., 1998), but it does not consider the socioeconomic variability that may also be associated with that location. 7.1.2 Requirement Study It is the intention of this research to enhance the flood-warning and emer- gency-planning industry with GIS technology. There are a number of organizations in the United Kingdom with different responsibilities within the flood indu stry (Table 7.1); consultant s and resea rch insti tutes are assigned projects to develop the roles of these organizations. As the industry does not have a single function, it was necessary to identify one aspect of technical research that could reasonably be undertaken with limited time and data, and yet provide a useful service. A GIS requirement study has been administered to evaluate the research needs of flood warning and emergency planning, but these particular needs are difficult to define ß 2007 by Taylor & Francis Group, LLC. TABLE 7.1 Flood Hazard Responsibilities in the United Kingdom Organization Responsibilities Legislative bodies Ministry of Agriculture, Fisheries and Food (MAFF), now Department of Environment, Food and Rural Affairs (DEFRA) have policy responsibility for flood and coastal defense in England and administers the legislation that enables work to be carried out. The Flood and Coastal Defence Programme is aimed at reducing risk to people and the developed and natural land by financially supporting, advising, and guiding flood and coastal defense operating authorities, and funding research programs. Following the 2000 floods, better definition of flood or erosion risk areas was identified as being of particular necessity to flood planning (HR Wallingford, 2000) Meteorological office Continuous monitoring of weather conditions and rainfall patterns from remote sensing and ground-based measurements falls under the authority of the meteorological office (MetOffice). Computer models simulate river discharge based on rain-gauge readings over time-periods in various parts of different catchments. If a flood situation arises, the MetOffice alerts the EA and local authorities to the possible threat Environment Agency (and the Scottish Environmental Protection Agency) The Environment Agency (EA) has the lead role in disseminating flood- warning messages with the help of local authorities; flood defense accounts for about 50% of the Agency’s annual budget (EA, 1996). There are a number of departments within EA to deal with various aspects of flood warning. The National Flood-warning Centre continuously monitors changes in the conditions of rivers, such as the effect of development on channel flow; and it is the interface between the agency and the public. The Emergency Management Team develops contingency planning policy on which it advises local authorities and coordinates the information flow during an emergency. The EMT liase with weather service providers and issue warnings and press releases during an emergency and are responsible for education campaigns prior to any particular event. EA regional offices deal with more localized issues with respect to flood-alleviation schemes and flood warning. There is some variation between EA regions in the scope and sophistication of the facilities available to support operational decision-making (Haggett, 1998) Police and local authorities Local planning and emergency considerations: It is the role of the police to organize localized planning and response on behalf of LA and EA guidelines. Once alerted to the onset of a flood event a command- and-control center is set up by the police, local warnings are issued, and emergency response teams dispatched. The police have roles in the evacuation of people at-risk and traffic management (Smith and Ward, 1998). Without detailed information on the social characteristics of different threatened communities, emergency planners and services can have great difficulty in reaching specific communities in need (Haggett, 1998). The police have endeavored to improve reliability and speed of flood-warning dissemination and focus on emergency response through the use of technology (Horner, 2000) ß 2007 by Taylor & Francis Group, LLC. owing to the dearth of a ppropria te litera ture. To overcome this problem , a series of intervie ws has been condu cted with man y of the key organizat ions from the flood ind ustry in the United Kingdom to supp lement findings from releva nt litera ture. The object of the inte rviews are twof old: to collate an audit of curren t GIS to co nsider how the techn ology is used in fl ood warning and emerge ncy planning, and iden tify areas where GIS are no t meeting their potenti al; a nd to conside r the opi nions of some of the leadi ng practitio ners in these areas, wh ich would significant ly ben efit the flood- warning and emerge ncy-plan ning pro cess. The audit shows that most system s deal with flood war ning and pre - ventio n, or emergency planning, but very few syst ems are used for em er- gency resp onse that re quires pre cise and up- to-date inform ation for effici ent decisio n-maki ng on how to respon d to chang es in ci rcumst ances (Table 7.2). No system s-in-use consi der all a spects of the flood indu stry, and ne arly all the use of GIS is onl y involv ed with research , possibl y indicating the deficien cy of actual running syst ems. Over all the system s are spar se in utilizi ng soc ioeconom ic data and as sessing fl oods accordi ng to popu lation and commodity risk . Advan ces of GIS may invo lve more soc ial consid er- ations of floodin g as the nece ssity for monitorin g flood- risk comes from the effect it may have on soc iety. It may also be fruitf ul to conside r a syst em that not on ly provides flood war ning but a lso assists in the emerge ncy planni ng and respons e of a flood in real time, anoth er use of GIS which is not being optim ally exploited . Real-tim e GIS may be useful in modify ing emerge ncy plans appr opriate ly duri ng a flood event as new da ta bec omes avai lable. Interviews included advances for research in the flood industry that organizations felt were important, and these were found to generally concur with ideas expressed in the literature. The so-called ‘‘living wi th hazards’’ philosophy (Alexander, 1997; Smith and Ward, 1998) has created the need for more effective initiatives to be researched within the roles of warning, TABLE 7.1 (continued) Flood Hazard Responsibilities in the United Kingdom Organization Responsibilities Insurance companies In different European countries, there are varying methods for insuring against flood damage. Countries with a high risk of flooding have responded in different ways. Austria and Belgium have state-funded schemes; Italy has insurance available that is rarely bought; and Netherlands has no insurance cover available other than for some industrial risks. The United Kingdom, with medium risk, is the only country in EU with 100% private insurance solutions (Ebel, 1999). Flood aid and insurance do nothing to mitigate and reduce the risk of future disasters, and such measures may be counterproductive if they continue to encourage settlement into high-risk areas (Smith and Ward, 1998). The insurance industry has recently discovered the value of flood-risk maps that combine flood depth with information onbuilding types within a given area, usually defined by its postcode (Rodda, 2001) ß 2007 by Taylor & Francis Group, LLC. Context Used System GIS Functionality Access Data Layers Included How Risk is Assessed Organization Responsible Name Flood Warning Flood Prevention Emergency Planning Emergency Response Research Assistance Customised System STandard GIS Software Real-Time Strategic Database Querying Mapping Map Querying Report Writing Mulit-Task Windows Model Integration Data Integration Used by Organization Used by other Organizations Public Meteorological Hydrological Topographical Land Use Social Economical Address Transport /Utilities Climate Patterns Water Depth Water Extent Damage Population CEH Wallingford General use CEH Wallingford + HR Wallingford HYDROWORKS EA a (Web site) Indicative floodplain EA NFWC b General use FHRC c General use FHRC REGIS Halcrow General use Home Office HAZMOD HR Wallingford EUROTAS HR Wallingford General use Integraph SCDOT Lancaster University CEMPS MetOffice ENVIRONMENT MetOffice SWIM The author would like to apologize for any systems that are omitted. The matrix has been constructed using knowledge gained from the requirements study and may not be definitive. The list only includes systems which were in use at the time the requirements study was undertaken, and not ones which were then in development. (e.g., FLOODWORKS for DEFRA). Notes: a Environment A g ency, b National Flood-warnin g Centre, and c Flood Hazard Research Centre, University of Middlesex TABLE 7.2 Audit of GIS in the Flood Industry (England and Wales) ß 2007 by Taylor & Francis Group, LLC. planning, and response. Emergency planners, police, and local authorities would benefit from GIS, but the technology does not currently play an important role. Traditionally, GIS technology has been used in supporting surface-water modeling and flood-hazard exposure analysis by providing the ability to integrate modeling results with other layers of information to enhance the decision-making process (Boyle et al., 1998). However, GIS provides the means of integrating different phenomenon such as social and geographical data, in order to increase the overall under- standing of the relationship between society and disaster (Dash, 1997). Technological solutions could be sought to improve the dissemination process with decision-support tools (Haggett, 1998) but for many flood planners the advantages of GIS are not considered or fully understood. For instance, the City of Edinburgh Council stores all information for responding to a flood within one paper file binder. During a hazard situ- ation, members of a committee sit around a table and discuss appropriate courses of action. Benefits of GIS and automated information are seen as negligible because flooding seldom occurs twice. The Thames police also resolve response management without the use of GIS, where and when it is necessary; a system that the users consider sufficient (Whittington, 2001). Conclusions of the requirements study identify communicating the flood message (education prior to and alerting during an emergency) and improving disaster response as two important advances in flood research. Both of these initiatives are common to the need for discriminating between different groups of people living within the floodplain. There are two ways that communities could be classified within the floodplain. First, since disaster vulnerability is partially socially constructed (Morrow, 1999), identifying different levels of social vulnerability could improve efficiency of warning and emergency response. For example, awareness that 75% of a community are non-English speakers could result in more appropriately tailored education and warning, where as the know- ledge that 50% of a co mmunity are aged over 75 years could help allocate the dispatch of sufficient help. Secondly, flood return periods (or scenarios) are effective ly an estimated probability of a flood occurring at any year. The flood risk map for England and Wales (Morris and Flavin, 1996) and the indicative floodplain map (Environment Agency, 2000) consider the maximum predicted flood but do not distinguish degrees of risk. Flood risk can vary within the area of a community and a detailed understanding of flood-risk variability could be extremely valuable to flood planners. Flood-vulnerability mapping could help prioritizing emergency dissemination where accurate flood data iden- tifies where and when different flood scenarios are going to occur. 7.1.3 Aims The conclusions of the requirement study are the basis for the direction taken by this research. Social vulnerability and flood vulnerability are ß 2007 by Taylor & Francis Group, LLC. calcu lated from socioeco nomic and flood- depth da ta. The broad appro ach is to merge the physica l ass essment of flood risk with the social as sessm ent of vuln erability to produce an IFV to the unit postc ode level. The index is used to create a pro totype decision- support tool that utilize s GIS func tionality to impr ove the efficiency of flood- war ning and emerge ncy planning, as well as havin g scope for em ergency resp onse. From this research , it is hoped to convi nce em ergency planners of few GIS benefits. The vuln erabi lity-inde x is not re quired in this research to be highl y accura te; it is the concep ts that are und er scrutiny. It is thought that the typ e dec ision-s upport tool is useable , given that sufficie ntly accurate da ta is av ailable. The mai n resea rch question s consid ered are . How can GIS be used to ass ist the identificati on of vuln erable groups wi thin commun ities in areas prone to floodin g? . What data provides the best indic ators of soc ial vuln erability? . What data would best ser ve the definiti on of flood- risk spat ial variabil ity? . Does the inte gration of the two datase ts improv e the vulne rabilit y index? 7.2 Methods 7.2. 1 Index of Social Vulnerabi lity The mode l is tested on a 30-km stretch of the River Tham es betwee n Eton and Walto n-on-Th ames. Socio economi c da ta is used to map an in dex of soc ial vulnerabi lity (ISV) at the level of enume ration districts (EDs) . Social vuln erability to a disaster may not only be affec ted by pover ty but is the over all ability to resp ond to a hazar d situat ion (Tu nstall, 1999). Certain phy sical and soc ial attr ibutes (age, race, and gend er) and living arr ange- ments (si ngle pare nt hou seho lds), wher e the relati onship wi th soc ial cl ass is not so well-de fined, a re likel y to have as mu ch, if not mo re effect on vuln erability as pove rty. Far from bein g mutual ly exclus ive, these factor s tend to occu r in combi nations that intensify risk exp onentiall y (Mor row, 1999). Data was obt ained to refle ct a wide ran ge of attributes that may increase (or dec rease) social vuln erability of a smal l commun ity. From discussion with experts, criteria expressed in the literature (e.g., Morrow, 1999; Tapsell, 1999, 2000; Tunstall, 1999; Dralsek, 2000; Environment Agency, 2000, 2001) and information that can reasonably be thought to determine social vulnerability, a restricted set of 10 domains have been chosen. The 1991 U.K. Census provides nine domains and the 10th one from the index of multiple deprivation; the calculations of a domain are constr ained from the avai lable source da ta (Tabl e 7.3). ß 2007 by Taylor & Francis Group, LLC. TABLE 7.3 Domains Used for Calculating the Index of Social Vulnerability Domain Reason for Inclusion Values Used Reason for Values Used Weighting Applied How Index Is Calculated Source Long-term illness [ED] People with illness may be restricted in their ability to respond effectively without assistance (Tunstall, 1999) % of long-term illnesses to total ED population Assumes all ill persons are equally dependent on others and thus equally as vulnerable None, all people with long-term illness are equally vulnerable % is standardized Census (1991) OAPs [ED] OAPs may be restricted in their ability to respond effectively (Tunstall, 1999) % of OAPs that are: (a) ill, (b) >75 years, and (c) live alone All OAPs are potentially vulnerable but being >75 years, ill, or living alone will increase the vulnerability (a)–(c) are given equal weighting (as cannot distinguish further variability) and multiplied together %OAPs 3 % >75 3 %live alone 3 %ill Results standardized Census (1991) Single parents [ED] Single heads of households are disproportionately disadvantaged following flooding because they are responsible for dependants who may not be able to act appropriately themselves (Morrow, 1999; Tapsell, 1999; Dralsek, 2000) Number of parents with children aged: (a) 0–4 (b) 0–4 and 5–15 (c) 5–15 Different aged children may have different abilities and having more than one child may affect how easily parents can cope in a hazard situation. Younger children are considered the most vulnerable, especially those that cannot walk When added, (a)–(c) makes up number of single parents. The weightings are applied by multiplying (a)–(c) by individual significance and totalling value; e.g., youngest children are given 33 vulnerability of older ones 3[%0 ] 4] þ 2[%0 ] 4 and 5 ] 15] þ 1[%5 ] 15] Results standardized Census (1991) (continued ) ß 2007 by Taylor & Francis Group, LLC. TABLE 7.3 (continued) Domains Used for Calculating the Index of Social Vulnerability Domain Reason for Inclusion Values Used Reason for Values Used Weighting Applied How Index Is Calculated Source Non-U.K. born [ED] People born outside the United Kingdom may not speak English as their first language or have cultural differences that affect understanding of flood warnings or methods of response (Morrow, 1999) % of non-U.K. born to total ED population Assumes all people born outside United Kingdom are equally vulnerable and just considers the proportion of the total population. (Data does not identify particular English-speaking nations) None, all people born outside the United Kingdom are potentially equally vulnerable % is standardized Census (1991) Business properties [ED] Less households may be threatened in areas where there are more business properties % of business properties to total ED properties Has a negative impact on social vulnerability due to smaller number of residential properties None, business properties have an equal effect on reducing social vulnerability % is standardized and multiplies by ] 1to consider negative impact Census (1991) Children [ED] As dependants are vulnerable themselves and increase the vulnerability of others (Morrow, 1999), they may not understand how to respond % of children to total ED population Assumes all persons are all dependent on others and therefore equally vulnerable. Further breakdown of ages is considered for single parents None, all children are equally vulnerable (conflicts with method for calculating single parent vulnerability) % is standardized Census (1991) ß 2007 by Taylor & Francis Group, LLC. [...]... flood) and negative to 0 (no flood), repeating the process for all scenarios The five scenario grids are literally added 0–1 m 1–2 m 2–3 m 3–4 m 4–5 m 5–6 m 6 7 m 7 8 m 8 70 m No data FIGURE 7. 1 (See color insert following page 328.) Modeled height above the river (HAR) (ß Crown Copyright= database right 20 07 An Ordnance Survey=EDINA supplied service.) ß 20 07 by Taylor & Francis Group, LLC TABLE 7. 5... in a GIS can easily identify areas affected by a particular flood scenario (Figure 7. 7) The potential of the indexes may be realized with the demonstration of possible applications FIGURE 7. 7 (See color insert following page 328.) Identifying vulnerable areas during a 25-year flood To the left is a close-up of the coarser resolution map to the right The green masks areas of the ISV that are safe and. .. flood industry what could be done if more accurate vulnerability indexes and flood-probability contours were produced, and further vulnerability research regards the findings as a useful contribution to further work, the present research will have been successful References Alexander, D., 19 97, The study of disasters, 1 977 –19 97: some reflections on a changing field of knowledge Disasters 21(4), 284–304... necessity and feasibility of targeting vulnerable households Disasters 23(4), 359– 372 HR Wallingford, 2000, National Appraisal of Assets at Risk for Flooding and Coastal Erosion—Technical Report HR Wallingford, SR 573 (Wallingford: HR Wallingford) Morris, D.G and Flavin, R.W., 1996, Flood Risk Map for England and Wales (Wallingford: Institute of Hydrology) Morrow, B.H., 1999 Identifying and mapping... community vulnerability Disasters 23(1), 1–18 Penning-Rowsell, E.C., Tunstall, S.M., Tapsell, S.M., and Parker, D.J., 2000, The benefits of flood-warnings: real but elusive and politically significant Journal of the Chartered Institute of Water Engineering and Management 14, 7 14 Plougher, A., 2000, The future of telematics and telephony in flood-warning, In Communicating the Flood Message Report Of... the social-vulnerability index can be chosen as required to help identify certain groups and any attributes that go with them, such as postcode which may be used in advance of a flood-situation for sending educational brochures (Figure 7. 8) In the event of a flood and with data indicating the return-period in occurrence, emergency response teams can quickly identify the vulnerable properties and postcodes... equally vulnerable % is standardized Census (1991) None, all properties without cars are equally vulnerable % is standardized Census (1991) None, the deprivation index is already calculated Values calculated from wards to EDs and standardized DETR (2001)a TABLE 7. 4 Weight Assigned to Each Vulnerability Domain Domain % Weight Deprivation Long-term illnesses OAPs Single parents Non-U.K born Businesses Children... forecasting and warning in England and Wales Journal for Chartered Institute of Water and Environmental Management 12(6), 425–432 Heywood, D.I., Cornelius, S., and Carver, S., 1998, Introduction to Geographical Information Systems (Harlow: Addison Wesley Longman) Horner, M.W., 2000, Easter 1998 floods Journal for Chartered Institute of Water and Environmental Management 14, 415–418 Jaspars, S and Shoham,... each postcode is divided into areas of different vulnerability (Figure 7. 2a) Each postcode requires a homogeneous vulnerability value; the values are dissolved (Arc=Info command) to eliminate the variance within one postcode (Figure 7. 2b) 7. 3 7. 3.1 Results Index of Social Vulnerability Once standardized the results of the domains and ISV cover the same range of values Comparison of values for individual... weight (Table 7. 4), and the value for each ED is adjusted accordingly Finally, the domain values are summed to create the index and adjusted to values between 0 and 100 to create the ISV, which is calculated from the equation: Social vulnerability ¼ 10 X Wi  D i i¼1 The ISV and individual domain values are assigned to ED boundary data using the unique ED-id This enables mapping the data and overlay . Study 135 7. 1.3 Aims 139 7. 2 Methods 140 7. 2.1 Index of Social Vulnerability 140 7. 2.2 Index of Flood Probability 144 7. 2.3 Combined Index of Flood Vulne rability 146 7. 3 Results 146 7. 3.1 Index. flood-risk areas in England and Wales (Environment Agency, 2000). Property worth over ß 20 07 by Taylor & Francis Group, LLC. £200 billion and agricultural land worth approximately 7 billion. of Environment, Food and Rural Affairs (DEFRA) have policy responsibility for flood and coastal defense in England and administers the legislation that enables work to be carried out. The Flood and Coastal